Communication systems and other applications utilizing electromagnetic energy often require some type of filtering to remove undesirable frequencies. However, conventional filter techniques may have certain drawbacks in terms of performance or costs associated with implementation or manufacturing.
For example, a conventional tuned element or cavity microwave filter may not adequately accommodate widely separated frequency bands, such as waveguide filters that are single mode for a lower frequency band but are overmoded at a higher frequency band. Although various techniques have been developed to increase the performance of this filter, these techniques may result, for example, in small gaps that may limit their application (e.g., in space based applications) due to potential multipactor action. This type of filter also may require complex construction, which may include machining, dip brazing, or electroforming, resulting in a time consuming and expensive process. As a result, there is a need for improved filter techniques.